The discussion centers on the reflection characteristics of a subwavelength conductor patch, specifically a metal stripe that is longer than the wavelength but narrower than one wavelength. It concludes that such a stripe will not reflect specularly due to the excitation of the metal stripe resonator, which re-radiates energy based on its radiation pattern. The importance of polarization is emphasized, as it affects the resonance and scattering behavior of the stripe. For radar stealth design, it is crucial to keep the width of the conductive stripe below one-tenth of the wavelength to prevent glinting effects.
PREREQUISITESElectromagnetic engineers, radar system designers, and researchers in stealth technology will benefit from this discussion, particularly those focused on the interaction of waves with subwavelength structures.
What if the incoming radiation was polarized in the plane of the length of the stripe, there should be no resonance then, correct? Would such polarizsd radiation reflect specularly?Baluncore said:Not specular. The incident energy would excite your metal stripe resonator, which would then re-radiate the incident energy according to the radiation pattern of the metal stripe scatterer. The magnitude of excitation would be the product of the direction of energy arrival and the scatterer radiation pattern, polarisation is important.
A large field of dipoles can “glint” because all the small spherical wavefronts can reinforce to make a plane wave where the angle of incidence equals the angle of reflection.
If your scatterer is narrower than one wavelength, it could still be a half wavelength wide which would make a long linear array of resonant dipoles. That might glint in a particular direction. You need to reduce the width of the conductive stripe to below about one tenth of a wavelength to prevent glint. That is important for radar stealth design.